Whats the difference between reflection and scattering of photon? (QFT)

This is due to the way that photons interact with electrons on the surface, with reflection involving virtual interactions with all of the electrons, while scattering involves being absorbed and re-emitted by a specific electron. Ultimately, the surface's properties and the type of interaction with electrons determine whether the photon will be reflected or scattered.
  • #1
enroger0
21
0
Just read Feynmen's QFT and been wondering the difference between photon reflection by a perfect mirror and photon scatter by say a rough surface.

In both cases, photons are said to be absorbed by electrons and re-emitted.

But in reflection case, photons get to "preserve" its wave information (wavefunction never collapse, phase increase by pi/2). I think in QFT, photons are said to have virtual interaction with all the electrons on the mirror?

In scattering case, photon is absorbed by a specific electron and re-emitted, destroying all wave information.

So what decide photon when to be reflected when to be scattered?

Thanks for the help, just a curious laymen here.
 
Last edited:
Physics news on Phys.org
  • #2
The difference between photon reflection and photon scattering is determined by the type of surface that the photons interact with. If the surface is perfectly smooth and reflective, then the photons will be reflected, preserving their wave information. If the surface is rough or non-continuous (i.e. made up of many smaller particles, such as a sandpaper-like material), then the photons will be scattered in multiple directions, losing all of their wave information in the process.
 

1. What is the fundamental difference between reflection and scattering of photons?

The main difference between reflection and scattering of photons is the direction of the outgoing photons. In reflection, the photons bounce off a surface at the same angle as the incoming photons, whereas in scattering, the photons are redirected in different directions.

2. How does the wavelength of the photons affect the process of reflection and scattering?

The wavelength of photons plays a crucial role in both reflection and scattering. In reflection, the wavelength of the photons remains unchanged, while in scattering, the wavelength of the photons can be altered depending on the type of scattering (e.g. Rayleigh or Mie).

3. Can you explain the concept of phase change in reflection and scattering of photons?

In reflection, the phase of the reflected photon remains the same as the incident photon, whereas in scattering, the phase of the scattered photon can be altered depending on the type of scattering. For example, in elastic scattering, the phase remains the same, but in inelastic scattering, the phase can change due to energy exchange with the scattering medium.

4. How do reflection and scattering of photons differ in terms of energy conservation?

In reflection, the energy of the reflected photon remains the same as the incident photon, while in scattering, energy can be transferred from the photon to the scattering medium, leading to a decrease in the energy of the scattered photon.

5. Can you provide real-life examples of reflection and scattering of photons?

Reflection is commonly observed in everyday objects, such as mirrors, where light reflects off the surface at the same angle. Scattering can be seen in the blue color of the sky, which is a result of Rayleigh scattering of sunlight by the Earth's atmosphere. Another example of scattering is the twinkling of stars, which is caused by the scattering of light by the Earth's atmosphere.

Similar threads

  • Quantum Physics
Replies
21
Views
980
  • Quantum Physics
Replies
29
Views
1K
Replies
16
Views
1K
  • Quantum Physics
2
Replies
38
Views
3K
Replies
25
Views
10K
  • Quantum Physics
Replies
8
Views
2K
Replies
8
Views
1K
Replies
3
Views
1K
Back
Top